Faculty of Engineering and Built Environment
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Item An evaluation of the applicability of the extended situational leadership model to lower level management in the South African construction industry(University of the Witwatersrand, 1990-08-10) Cocotos, GeorgeThe vast majority of theories and models that have been developed around the concept of leadership have been conceptualized, and tested in the USA and other countries outside South Africa as discussed in the literature survey, Chapter 2 of this dissertation). Furthermore, the models developed have largely been theoretical models aimed to help leaders only to identify the most appropriate leadership style to use. None have however attempted to develop a model that leaders can use to implement the most appropriate leadership style once it has been chosen. Consequently, A D Jaff, using the most integrated and recently developed Situational Leadership Theory and Mode 1 of Hersey and Blanchard as a data base, developed the first leadership implementation model - The Extended Situational Leadership Model. Since AD Jaff's implementation model is a combination of various other leadership mode ls and theories, in order to fully understand the development of the Extended SL Model, all the relevant models are researched in this dissertation (see Chapter 2). This dissertation attempts to test the applicability of the Extended SL Model in a practical construction environment in South Africa. It further attempts to make adaptations to the model where relevant, after testing its performance value through the administration of 3 questionnaires to a sample of potential/practising black leaders (on-site construction managers). (This lS surveyed in Chapters 3 to 6 of this dissertation). The objective of this dissertation is therefore to attempt to test, and where necessary, to adapt AD Jaff's Extended SL Model so that : 1) this theoretical model may be implemented practically in a South African construction working environment (i.e. to prove that the mode 1 does work in practice) ( see Chapter 4). and to test whether 2) the adapted mode 1 is applicable for the training of future black Low-Level leaders in the South African construction environment. The adapted form of the model will, I believe, prove to be a useful tool for the training of black leaders within the South African construction organisations, where the volatile industry and changing economic and political environment of South Africa with ensure the emergence of black South African Low Level leaders in the construction industry in the near future.Item Just-in-time development model for a sub-level caving underground mine in Zimbabwe.(The Southern African Institute of Mining and Metallurgy., 2003-04) Musingwini, C.; Minnitt, R.C.A.; Phuti, D.; Makwara, F.Traditionally, mineral reserves management at most underground mines in Zimbabwe focus on maintaining large mineral reserves so that the time between development and production is as long as possible. Historical data at Shabanie mine, a Zimbabwean sub-level caving underground mining operation, confirms this practice. However, the high cost of underground development means that the luxury of large buffer mineral reserves cannot be justified. Furthermore significant increases in the costs of production, exacerbated by the current unfavourable economic climate, make the wisdom of extending development workings well ahead of use questionable. Poor ground conditions at Shabanie mine, mean that some development ends have to be re-mined two or three times due to partial or complete closure between the time they are mined and the time they are utilized. In order to reduce the inordinately high support costs associated with closure of development ends a new 'Just-in-time' (JIT) approach that provides development ends as and when they are needed, has been adopted. Accordingly a model to determine an appropriate 'just-in-time' rate of development has been created. The JIT development model indicated that the mine could reduce development rates from 330 m/month in 2001, to 160 m/month in 2002 and achieve savings of about 50% on annual support costs, but still assure customers of a long-term product supply. The mine accepted the model in November 2001 and began implementing it in 2002. Results of the implementation will be reviewed in 2003.Item First cycle experience of a business process re-engineering programme at Shabanie Mine.(The Southern African Institute of Mining and Metallurgy., 2005-04) Musingwini, C.; Muzoriwa, C.; Phuti, D.; Mbirikira, D.In the past ten to fifteen years, many organizations have applied business process re-engineering (BPR) to significantly improve their business competitiveness or stave off closures. The mining industry in Southern Africa is no exception and documented examples can be drawn from South Africa. Although the concept is superficially simple, its application has been marked by a high failure rate of about 70 per cent because it has been generally misunderstood. Shabanie mine, a chrysotile asbestos fibre producer in Zimbabwe took cognisance of this fact by cautiously embarking on a modular BPR programme in October of 2002. A year was used as a complete cycle or module for re-evaluation of the programme. Shabanie mine adopted BPR as part of management efforts to remain competitive amid serious threats to operational viability. These threats included hyper-inflation driven rising production costs, a declining world asbestos market and a possibility that Russia could take over the shrinking world asbestos market by dumping low-priced asbestos fibre. The only competitive advantage that the mine had was the high quality of its long-fibre chrysotile asbestos. The major BPR thrust was therefore to redesign processes for improved productivity and ultimately achieve a lower cost per ton of final asbestos fibre product. In addition, corporate culture change and cost-saving were also factored into the programme. This paper discusses the implementation experience of the BPR programme at the mine. The main BPR beneficial highlights are improved productivity, sizeable cost-savings, positive corporate culture change and identification of secondary projects. One of the lessons learnt from this programme is that mining companies will have to deal with the HIV/AIDS pandemic if they are to sustain high levels of productivity into the future.Item Technical operating flexibility in the analysis of mine layouts and schedules.(The Southern African Institute of Mining and Metallurgy., 2007-02) Musingwini, C.; Minnitt, R.C.A.; Woodhall, M.Often overlooked factor in the analysis of mine layouts and schedules is technical operating flexibility (or tactical flexibility), mainly due to its nebulous nature. By glossing over technical operating flexibility the resultant mine layouts and schedules may be suboptimal. The need to incorporate technical operating flexibility into the analysis and comparison of mine layouts and schedules is increasing in importance. The nature of technical operating flexibility is illustrated, previous work on valuing of operating flexibility reviewed, and a proposal made on how technical operating flexibility can be quantified for tabular reef mines by using a platinum reef deposit as a case study. Once technical operating flexibility has been quantified it becomes possible to explore its incorporation into the analysis of mine layouts and schedules and subsequent optimization processes. This paper is a revised version of a paper presented in the Proceedings of the Second International Platinum Conference, 'Platinum Surges Ahead' in 2006. The work described in this paper is part of a current PhD study at the University of the Witwatersrand.Item Modelling open pit shovel-truck systems using the Machine Repair Model.(The Southern African Institute of Mining and Metallurgy., 2007-08) Krause, A.; Musingwini, C.Shovel-truck systems for loading and hauling material in open pit mines are now routinely analysed using simulation models or off-the-shelf simulation software packages, which can be very expensive for once-off or occasional use. The simulation models invariably produce different estimations of fleet sizes due to their differing estimations of cycle time. No single model or package can accurately estimate the required fleet size because the fleet operating parameters are characteristically random and dynamic. In order to improve confidence in sizing the fleet for a mining project, at least two estimation models should be used. This paper demonstrates that the Machine Repair Model can be modified and used as a model for estimating truck fleet size in an open pit shovel-truck system. The modified Machine Repair Model is first applied to a virtual open pit mine case study. The results compare favourably to output from other estimation models using the same input parameters for the virtual mine. The modified Machine Repair Model is further applied to an existing open pit coal operation, the Kwagga Section of Optimum Colliery as a case study. Again the results confirm those obtained from the virtual mine case study. It is concluded that the Machine Repair Model can be an affordable model compared to off-the-shelf generic software because it is easily modelled in Microsoft Excel, a software platform that most mines already use. This paper reports part of the work of a MSc research study submitted to the University of Witwatersrand, Johannesburg, South Africa.Item South African Architectural Record(Institutes of South African Architects and the Chapter of South African Quantity Surveyors, 1943)South African Architectural HistoryItem South African Architectural Record(Institutes of South African Architects and the Chapter of South African Quantity Surveyors., 1945)South African Architectural History.Item South African Architectural Record(Institutes of South African Architects and the Chapter of South African Quantity Surveyors., 1944)South African Architectural HistoryItem For Us(Witwatersrand University Architecture School, 1962) Jones, Patrick (ed)This exhibition is an expression of our search for a way in which we can, with conviction, face a situation deprived of a centre and a living purpose. In the buildings presented in this exhibition we find the evidence of a way of building that has not lost contact with the basic facts and mysteries of daily life.....The exhibition was more a poslng of a question than a formulatlon of a new vernacular.Item Clinic Building(Self published, 1980-01) Nimpuno, KrisnoThe objective of constructing low cost health buildings is not simply to build cheaply, but rather to construct fully adequate facilities for the lowest possible cost; or, in other words, to achieve a maximum health care capacity from each invested dollar. This may seem to be a very superficial remark, but there are in reality staggering differences in costs between hospitals of equal capacity within almost each of the LDCs, which give us ample reason for questioning the present practice. Does anyone really, helieve that ,medical €are .is ten times more effective in a ten times costlier hospital bed? Does anybody believe that a reasonable hospital bed/population ratio can be achieved with high rise, air conditioned hospitals in countries with a GNP/Capital of less than $500:- per annum? The answer is naturally no. Nobody believes that. But why do governments and technical assistance agencies build such costly facilities? The answer is that the elites taking those decisions are not sincere in their proclaimed efforts to provide equal care for the whole nation.